[libvirt-users] libvirt hang on domain attemp to create domain

[Michal Privoznik]

On 19.06.2013 21:24, Александр wrote:
> В письме от Среда, 19-июн-2013 09:35:27 пользователь Michal Privoznik написал:
>> On 18.06.2013 22:21, Александр wrote:
>>> В письме от Вторник, 18-июн-2013 12:10:41 пользователь Michal Privoznik
>>>
>>> написал:
>>>> On 18.06.2013 07:14, Александр wrote:
>>>>> good day, i am trying to create domain via virDomainDefineXML. and my
>>>>> program hanging, also i failed to caonnect to libvirt daemon with
>>>>> virt-manager after this, only killing libvirtd via SIGKILL and
>>>>> restarting
>>>>> it solveing hang (i mean after restart i able to connect with
>>>>> virt-manager), i using following domain xml
>>>>>
>>>>> <?xml version="1.0" encoding="UTF-8"?>
>>>>> <domain type="kvm">
>>>>>
>>>>>   <tittle>Automatically created domain with default
>>>>>   configuration</tittle>
>>>>>   <name>vm1</name>
>>>>>   <description>no description</description>
>>>>>   <os>
>>>>>   
>>>>>     <type>hvm</type>
>>>>>     <boot dev="cdrom"/>
>>>>>     <boot dev="hd"/>
>>>>>   
>>>>>   </os>
>>>>>   <vcpu>1</vcpu>
>>>>>   <memory unit="MB">512</memory>
>>>>>   <cpu model="host-model">
>>>>>   
>>>>>     <topology sockets="1" cores="1" threads="1"/>
>>>>>   
>>>>>   </cpu>
>>>>>   <clock offset="localtime"/>
>>>>>   <devices>
>>>>>   
>>>>>     <graphics type="vnc" autoport="yes" password="admin"/>
>>>>>     <channel type="unix">
>>>>>     
>>>>>       <source mode="bind" path="/var/run/vm1.sock"/>
>>>>>       <target type="virtio" name="org.guest_agent.0"/>
>>>>>     
>>>>>     </channel>
>>>>>   
>>>>>   </devices>
>>>>>
>>>>> </domain>
>>>>>
>>>>> i have this calls on stack
>>>>>
>>>>> 0  0x00007ffff48c1750  __poll_nocancel
>>>>> 1  0x00007ffff649e5ca  virNetClientIOEventLoop
>>>>
>>>> This is just probably a client waiting for the corresponding libvirtd to
>>>> provide a reply message. Are you able to get libvirtd debug logs so we
>>>> can see what's going on?
>>>>
>>>> http://wiki.libvirt.org/page/DebugLogs
>>>>
>>>> BTW, what's the libvirt version you are running?
>>>>
>>>> Michal
>>>>
>>>>> 2  0x00007ffff649ed96  virNetClientSendInternal
>>>>> 3  0x00007ffff64a0443  virNetClientSendWithReply
>>>>> 4  0x00007ffff64a0daa  virNetClientProgramCall
>>>>> 5  0x00007ffff6478566  callFull.isra.2
>>>>> 6  0x00007ffff6487fa2  remoteDomainDefineXML
>>>>> 7  0x00007ffff6449d2f  virDomainDefineXML
>>>>> 8  0x0000000000426941  virt_domain::create
>>>>> /home/sss/install/git/work/avirt/vm_pool/vm_pool/libvirt.cpp  295
>>>>> 9  0x000000000040c1a9  main
>>>>> /home/sss/install/git/work/avirt/vm_pool/vm_pool/main.cpp  40
>>>>>
>>>>> what i am doing wrong ?
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> libvirt-users mailing list
>>>>> libvirt-users at redhat.com
>>>>> https://www.redhat.com/mailman/listinfo/libvirt-users
>>>
>>> i have libvirt version 1.0.6, debug log in attachment.
>>
>> Yuck, this is 1.0.6; Well, from the logs it seems like the daemon is
>> stuck. Can you attach to the libvirtd while it's being stuck and run 't
>> a a bt' and post the result? I wonder if we have a deadlock somewhere.
>>
>> Michal
> 
> if i correctly understand you, you need debugger backtrace after libvirtd 
> stuck ?, if so, here is bt from gdb

You understand correctly. However, simple 'bt' doesn't show what's going
on in other threads - libvirtd is multi threaded.

> 
> (gdb) bt
> #0  0x00007f00c1ae876d in poll () from /lib64/libc.so.6
> #1  0x00007f00c203cfcb in virEventPollRunOnce () from /usr/lib64/libvirt.so.0
> #2  0x00007f00c203ba4d in virEventRunDefaultImpl () from 
> /usr/lib64/libvirt.so.0
> #3  0x00007f00c214a5cd in virNetServerRun () from /usr/lib64/libvirt.so.0
> #4  0x00007f00c2aea08a in main ()

So all we see here is the libvirtd event loop. That's why we need 't a a
bt' which is 'thread apply all backtrace' which will run 'bt' over all
threads.

Michal